The Applicant has developed a range of Memjet® inkjet printers as described in, for example, WO2011/143700, WO2011/143699 and WO2009/089567, the contents of which are herein incorporated by reference. Memjet® printers employ a stationary printhead in combination with a feed mechanism which feeds print media past the printhead in a single pass. Memjet® printers therefore provide much higher printing speeds than conventional scanning inkjet printers.
Sheet-fed pagewide printers typically spit ink between pages (as well as on the page) in order to ensure inkjet nozzles are healthy and remain hydrated with ink. Without inter-page spitting nozzles are at risk of dehydration and may require additional maintenance interventions, such as wiping or pressure-purging. Therefore, sheet-fed printers typically have a platen equipped with a spittoon for receiving spitted ink when the printhead is not printing onto a page. For example, US2011/0279538, the contents of which are incorporated herein by reference, describes a platen having a gap between upstream and downstream ribs with an absorbent spittoon material disposed in the gap below the ribs. U.S. Provisional Application No. 62/505,736 filed 12 May 2017, the contents of which are incorporated herein by reference, describes a platen having a wick bar configured for managing ink aerosol and handling paper dust generated during high-speed printing.
Pigment-based ink presents unique challenges for ink collection compared to dye-based inks. Whereas dye-based inks may be collected on an absorbent material with dyes remaining solubilized in the aqueous medium, pigment-based ink are less amenable to collection on absorbent materials since the insoluble pigment tends precipitate from the ink and clog the material, thereby reducing the material's wicking capabilities.
U.S. Pat. No. 8,091,978 (assigned to HP Inc.) describes a spittoon arrangement suitable for collecting pigment-based inks. In this arrangement, rollers having non-absorbent surfaces are positioned beneath staggered slots in a platen and ink is scraped from the rollers for removal.
It would be desirable to provide an improved spittoon for an inkjet printhead suitable for collecting pigment-based ink spitted from the printhead. It would further be desirable to provide a spittoon which manages airflow for aerosol collection as well as collecting the spitted ink.